Unlike bacteria such as Escherichia coli and Bacillus subtilis, several species of freshwater cyanobacteria are known to contain multiple chromosomal copies per cell, at all stages of their cell cycle. We have characterized the replication of multi-copy chromosomes in the cyanobacterium Synechococcus elongatus PCC 7942 (hereafter Synechococcus 7942). In Synechococcus 7942, the replication of mu...

UNLABELLED The "Candidatus Synechococcus spongiarum" group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a "Ca. Synechococcus spongiarum" group member was recently published, providing evidence of genome reduction by loss of genes involved in seve...

The relatedness of several marine Synechococcus spp. was estimated by DNA hybridization. Strains isolated from various geographical locations and representing a diversity of DNA base compositions and phycobiliprotein profiles were compared by restriction fragment length polymorphisms for a number of genes. DNAs from two marine red algae and a cryptomonad alga (which exhibit a phycobiliprotein c...

Marine cyanobacteria play an important role in global carbon cycling and are a potential source of polyglucans for biotechnological purposes. This report provides the draft sequence of an Indian marine cyanobacterium, Synechococcus elongatus BDU 130192, which shows fast growth and high polyglucan content. The genome sequence will help in understanding the unique properties of this organism.

Photosynthetic picoplankton, represented primarily by the genera Synechococcus and Prochlorococcus, are major contributors of biomass and primary production in oligotrophic oceanic ecosystems (JOHNSON & SIEBURTH, 1979; WATERBURY et al., 1979; PARTENSKY et al., 1999a). In the oligotrophic Mediterranean Sea, picophytoplankton has a great contribution to total phytoplankton biomass and production ...

Photosynthetic microbes are of emerging interest as production organisms in biotechnology because they can grow autotrophically using sunlight, an abundant energy source, and CO₂, a greenhouse gas. Important traits for such microbes are fast growth and amenability to genetic manipulation. Here we describe Synechococcus elongatus UTEX 2973, a unicellular cyanobacterium capable of rapid autotroph...

The two most abundant marine autotrophic prokaryotes, Prochlorococcus and Synechococcus, often have different distributions in the ocean. For example, Synechococcus is restricted to the first 100 m, whereas Prochlorococcus extends much deeper in oligotrophic waters. This is in part explained by differences in adaptation to nutrient and light regimes. However, they could also be subjected to dif...

In most cyanobacteria, the gene rbcX is co-transcribed with the rbcL and rbcS genes that code for the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Previous co-expression studies in Escherichia coli of cyanobacterial Rubisco and RbcX have identified a chaperonin-like function for RbcX. The organization of the rbcLXS operon has, to a certain extent, precl...

Posttranslational regulation of nitrate assimilation was studied in the cyanobacterium Synechocystis sp. strain PCC 6803. The ABC-type nitrate and nitrite bispecific transporter encoded by the nrtABCD genes was completely inhibited by ammonium as in Synechococcus elongatus strain PCC 7942. Nitrate reductase was insensitive to ammonium, while it is inhibited in the Synechococcus strain. Nitrite ...

Cyanobacteria of the genera Synechococcus and Prochlorococcus dominate the prokaryotic component of the picophytoplankton in the oceans. It is still less than 10 years since the discovery of phages that infect marine Synechococcus and the beginning of the characterisation of these phages and assessment of their ecological impact. Estimations of the contribution of phages to Synechococcus mortal...